Seal for a suspension drilling device



April 7; 1,964 J. s. BECK 3,128,102

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Bymm /w United States Patent Office 3,128,102 Patented Apr. 7, 19643,128,102 SEAL EUR A SUSPENSIGN DRILLING DEVICE Julius S. Beck, 2785Cherry Ave., Long Beach 6, Calif. Filed Apr., 19, 1961, Ser. No. 104,0671t) Ciaims. (Cl. 277-17) This invention relates to new and usefulimprovements in the art of oil well drilling, and in particular theinvention concerns itself with a suspension drilling device and jar ofthe general type disclosed in my prior Patents Nos. 2,819,878 and2,819,879, both dated January 14, 1958.

In the operation of devices of this type, it is important to takecognizance of hydrostatic, hydraulic and rock pressures, and of thedirection in which these pressures act to cause circulation or reversecirculation of fluid in the well and in the drill pipe. Movement of thefluid in the well through the drill is undesirable, particularly underthe relatively high pressures often encountered, since the abrasiveproperties of the uid tend to cause scoring and eventual washouts. Thus,sealing means are usually provided in such devices to prevent theundesirable uid movement, and the principal object of this invention isto provide sealing means of novel construction and operation, which aremore eifective and dependable than sealing means of conventional types.

With the foregoing object in View and such other objects and features aswill become apparent as this specification proceeds, the invention willbe understood from the following description taken in conjunction withthe accompanying drawings, wherein like characters of reference are usedto designate like parts, and wherein:

FIGURE 1 is a View of the device or tool, partly in vertical section andpartlyv in elevation, showing the same in a collapsed or retractedposition;

FIGURE 2 is a view similar to that shown in FIGURE l but illustratingthe tool in its extended position;

FIGURE 3 is a cross-sectional view, taken substantially in the plane ofthe line 3 3 in FIGURE l;

' FIGURE 4 is a cross-sectional view, taken substantially in the planeof the line 4 4 in FIGURE l;

FIGURE 5 is a cross-sectional view, taken substantially in the plane ofthe line 5 5 in FIGURE l;

FIGURE 6 is a cross-sectional view, taken substantially in the plane ofthe line 6 6 in FIGURE 2;

FIGURE 7 is a fragmentary elevational view of the mandrel;

FIGURE 8 is a fragmentary vertical sectional View of the body or barrel;

FIGURE 9 is a cross-sectional View, taken substantially in the plane ofthe line 9 9 in FIGURE 7;

FIGURE 10 is a cross-sectional view, taken substantially in the plane ofthe line 18-10 in FIGURE 8;

FIGURE ll is a cross-sectional View, taken substantially in the plane ofthe line 11 11 in FIGURE 7;

FIGURE l2 is an enlarged, fragmentary View, partly in vertical sectionand partly in elevation, showing the lower end portion of `FIGURE 1 ingreater detail;

FIGURE 13 is a View, similar to that shown in FIG- URE l2 andillustrating the lower end portion of FIG- URE 2 in greater detail;

FIGURE 14 is a cross-sectional view, taken substantially in the plane ofthe line 14 14 in FIGURE 13;

FIGURE 15 is a cross-sectional view, taken substantially in the plane ofthe line 15 15 in FIGURE 13; and

FIGURE 16 is a fragmentary view, partly in vertical section and partlyin elevation, of the lower end portion of FIGURE 1 and showing inelevation apparatus used for pressure loading the compensating chamberof the tool.

For purposes of orientation it may be noted that FIG- URES 1 and 2 aretaken substantially in the planes of the lines 1 1 and 2 2,respectively, in the respective FIG- URES 3 and 6.

Referring now to the accompanying drawings in detail, the suspensiondrilling device and jar of the invention is designated generally by thereference numeral 20 and embodies in its construction a tubular body orbarrel 21 accommodating therein a slidable tubular mandrel 22. The upperend of the mandrel 22 is provided with an enlarged, internallyscrew-threaded box 23, while the lower end of the barrel 21 is providedwith a reduced, externally screw-threaded sub or pin 24, whereby theentire device may be connected to the drill pipe in the usual manner.The underside of the enlarged box 23 affords an annular shoulder 25which is engageable with the top of a split nut 26 provided in the upperend of the barrel 21, so that when the tool is contracted as shown inFIGURE 1, the abutment of the shoulder 25 with the nut 26 serves as astop for downward sliding movement of the mandrel in the barrel, thuscreating an impact for jarring the barrel and the drill stringtherebelow. The mandrel 22, of course, passes slidably through the nut26 and the split formation of the latter facilitates its installation orremoval Without pulling the mandrel out of the barrel.

The intermediate portion of the mandrel 22 is provided with an integralring 27 which is engageable with the underside of the nut 26 to limitthe extent of upward sliding of the mandrel in the barrel and also tocreate an impact or jarring action on the up stroke. Moreover, themandrel is provided below the ring 27 with vertically spaced, integralkeys 28 and with vertical ribs 29 disposed at one side of the keys inthe respective sets, the sets of keys and ribs being shown as spacedcircumferentially of the'mandrelfor coaction with vertically andcircumferentially spaced lugs or bosses 30 which are provided within theintermediate portion of the barrel 21, whereby the mandrel may bereleasably locked in a selected position longitudinally of the barreland whereby torque may be transmitted from the mandrel to the barrel insubstantially the same manner as in my aforementioned Patents No.2,819,878 and 2,819,879.

The entire length of the mandrel 22 is provided with an axial bore orpassage 31 for drilling iluid and the lower end portion of the mandrel,indicated at 22a, is diametrically reduced so as to accommodate the sealassembly which is designated generally by the numeral 32. This sealassembly is located within the lower region of the barrel designated as21a in FIG. l, While the upper region 21b accommodates the jarring means27, 2S, 29, 30. The axial mandrel passage 31 is of suflcient diameter topermit survey or other instruments to be lowered therethrough, and itwill be also noted that the upper end of the barrel 21 whichaccommodates the nut 26 is large enough to allow passage of the largestdiameter of the mandrel during assembly and disassembly of the tool whenthe nut 2d is removed.

Relief holes 33 may be provided in the barrel 21 for uid entrappedbetween the ring 27, keys 28, ribs 29 and the bosses 30 in the barrel,and the lower end portion 21a of the barrel which accommodates the sealassembly 32 constitutes a pressure compensating chamber or cylinder 34,as will presently become apparent.

The seal assembly 32, located on the diametrically reduced portion 22aof the mandrel, consists of two or more vertically spaced sealing units34 and a resiliently compressible spacer or spring 35 therebetween. Eachof the units 34 comprises a pair of bevelled sealing rings 36 of lead,or the like, and a ring 37 of rubber, or the like, interposedtherebetween, the ring 37 having bevelled surfaces in engagement withthe bevelled rings 36 so that when the unit 34 is subjected to axialpressure, the rings 36 urge the ring 37 radially outwardly into sealingengagement with the wall of the chamber 34 in the barrel portion 21a,such sealing engagement becoming greater with increasing of the axialpressure applied to the unit7 as will be clearly understood,

The assembly 32 also includes spacers or washers 3S interposed betweenthe sealing units 34 and the spacer 35; a slidably mounted sleeve 39,additional spacers or washers 49 between the sleeve 39 and the lowerunit 34'; and a retaining nut 41. These various components of the sealassembly 32 are positioned on the mandrel portion 22a prior to theinstallation of the mandrel in the barrel, the nut 41 being threaded onthe lower end of the mandrel only to a sufficient extent to retain theparts assembled during installation of the mandrel in the barrel, butinsuiicient to expand the rings 37 to a point or extent which wouldrender installation of the mandrel in the barrel difficult. The mandrelis installed in the barrel in the contracted position of the device asshown in FIGURES 1 and 12 so that the nut 41 is readily accessiblethrough the hole or passage 24a in the pin 24, whereupon a Spanner typewrench is inserted through the passage 24a to to engage kerfs 42 formedin the outer or lower end of the nut, whereby full tightening of the nuton the mandrel may be effected. The nut 41 is equipped at one sidethereof with an insert 43 of Teflon, or the like, which is engaged andcut by the threads on the mandrel during the nut tightening operationand thus serves to lock the nut against backing ofi.

The upper sealing unit 34 abuts an annular shoulder 31' existing on themandrel 22 at the upper end of the diametrically reduced mandrel portion22a, and when the nut 41 is tightened as shown in FIGURE 13, theresilient spacer or spring 35 becomes somewhat compressed so that therings 37, urged outwardly by the rings 36, are brought into good sealingcontact with the wall of the chamber 34 in the barrel 21, thus formingan effective seal in both upward and downward directions. It will beobserved that the lower portion of the barrel 21 is provided with aninternal shoulder 44 which is engaged by the lower end of the sleeve 39when the device is fully contracted, as shown in FIGURE 12. In thisposition the sleeve 38 slides the lower sealing unit 34 upwardly on themandrel portion 22a, thus causing compression of the sealing means 32 inthe axial direction to a full extent, and providing a full sealingeffect. It will be noted that the compression of the sealing meanscaused by engagement of the sleeve 39 with the shoulder 44 takes placeindependently of the tightening of the nut 41, the latter having becomeseparated from its abutment with the sleeve 39 when the mandrel is sliddownwardly to the full extent relative to the barrel, as shown in FIGURE12.

When it is desired to pressurize the sealing means by force other thanand in addition to the pressurizing effect created by the tightening ofthe nut 41, the mandrel is moved to a position where the lower end ofthe sleeve 39 is out of contact with and above the shoulder 44 as shownin FIGURE 16, and grease or some other fluid is admitted under pressureinto the chamber 34 between the units 34' of the seal assembly, thisbeing effected through a check valve 45, or the like, provided in thesidf:l of the barrel portion 21a in communication with the chamberportion between the units 34. For such purpose, the grease or otherfluid is conveyed to the valve 45 by a suitable hose 46 from a supplytank 47 by a suitable pump 48, a pressure gauge 49 being provided on thehose or line 46 so that the pressure loading of the chamber of the sealassembly may be carried out to the extent required by the hydrostatic,hydraulic and rock pressures of a particular well.

Such pressures in or at the well bore may attempt to cause reversecirculation of fluid upwardly through the drill stem, but the inventioncompensates for such pressures so as to prevent leakage of the fluidupwardly between the mandrel and the barrel where the abrasive nature ofthe fluid would cause premature wear of parts. For this purpose theinvention utilizes the radially expansible sealing means between themandrel and the barrel, so that with such sealing means in the expandedposition, upward leakage ofiluid between the mandrel and the barrelcannot take place. In the one and same embodiment of the invention thesealing effect may be accomplished in a variety of different ways. Forexample, the seal units 34 may be radially expanded by tightening of thenut 41. Alternatively, they may be expanded by inward or downwardsliding of the mandrel in the barrel so that the sleeve 39 abuts theshoulder 44, in which event the force-exerting effect of the nut 41 isnot necessary. Or, the seal units may be expanded by introduction offluid under pressure through the valve 45 into the chamber 34 betweenthe seal units, such pressurized fluid serving to exert an axial forceon the seal units to radially expand them, regardless of whether thelower seal unit 34 is prevented from downward sliding by the nut 41 orby engagement of the sleeve 39 with the shoulder 44. Or, the seal unitsmay be expanded by pressure of fluid existing in the barrel below themandrel, that is, within the hollow sleeve 39, in which event the sleevewill be forced upwardly by such fluid pressure and, by eX- erting anaxial force on the seal units, will radially eX- vpand the same. In thelast mentioned instance the sealing action is truly automatic andresponsive to fluid pressure within the well bore and, as such, it isquite independent of the nut adjusting means 41 as well as of theabutment means 39, 44. In the event that the fluid pressure in the wellbore becomes too great, it may be compensated for or minimized byintroduction of uid under pressure into the seal chamber 34 through thevalve 45, so as to prevent over-compression of the spring 35, it beingnoted that introduction of fluid under pressure into the chamber 34assists the action of the spring 35 to keep the seal units 34' apart.

Over-compression of the spring 35 is to be avoided if the spring is toperform a useful function in absorbing or dampening shocks incident tojarring of the tool. While the shocks and jars are desirable forloosening an article or object stuck in the well, nevertheless, thedampening action afforded by the spring takes the initial shock irnpactand thereby prevents cracking or other damage of the parts, while stilldelivering a major portion of the impact to the stuck object. Again, inthis instance it will be noted that introduction of fluid under pressureinto the chamber 34 assists the action of the spring 35, so that theunit may be pre-loaded as desired, not only for shock dampeningpurposes, but also for counteraction of excessive bore pressures asalready mentioned.

It will be apparent from the foregoing that the portion of the chamber34 between the units 34' of the seal assembly 32 provides what may bereferred to as a loading zone of the tool, which may be pressure loadedwith grease or other suitable fluid so as to compensate for hydrostatic,hydraulic and rock pressures of the well. The arrangement of thisloading zone is such that 'it moves with the seal assembly duringmovement of the mandrel in the barrel without loss of pressure orleakage of the seal units. The seal assembly thus prevents undesiredmovement of well fluid through the tool, and the pressure-loadedcompensating chamber of the seal assembly affords a shock absorbing anddampening effect in the balancing of pressures in the tool. It will bealso 0bserved that the seal assembly functions effectively withoutdepending upon the mechanical movement of the mandrel in the barrel andwithout being affected by the jarring action of the tool.

While in the foregoing there has been described and shown the preferredembodiment of the invention, various modifications may become apparentto those skilled in the art to which the invention relates, Accordingly,it is not desired to limit the invention to this disclosure and variousmodifications and equivalents may be resorted to, falling within thespirit and scope of the invention as claimed.

What is claimed as new is:

1. In combination with a drill string, a tubular body connected at oneend thereof to a section of said drill string, a tubular mandrelslidably mounted in said body and extensible therefrom, the extendingend of said mandrel being connected to another section of the drillstring, means limiting longitudinal sliding movement of said mandrel andmeans limiting rotational movement of the mandrel in said body, the endportion of said mandrel in said body being diametrically reduced andproviding an abutment shoulder, a iirst radially expansible seal unitpositioned on said reduced portion of the mandrel in abutment with saidshoulder, a second radially expansible seal unit positioned on saidreduced mandrel portion in spaced relation from said iirst seal unit,resiliently conipressible means interposed between the iirst and secondseal units for spacing the same apart, and a screwthreaded elementpositioned on said reduced mandrel portion in abutment with said secondseal unit, whereby upon tightening of said screw-threaded element saidseal units may be radially expanded into engagement with the insidesurface of said tubular body.

2. The combination as defined in claim l wherein the interior of saidtubular body between said spaced seal units constitutes a pressurecompensating chamber, a valve provided in said tubular body incommunication with said chamber, and means disposed exteriorly of saidbody and connected to said valve for introducing fluid under pressureinto said chamber.

3. The combination as defined in claim l wherein said resilientlycompressible means comprise a compression spring surrounding saidreduced mandrel portion and having its ends in abutment with therespective seal units.

4. In a suspension drilling device and jar, the combination of a tubularbarrel adapted at one end thereof for connection to a drill stringsection, a tubular mandrel slidable in said barrel and projectingthrough the other end thereof for connection to another drill stringsection, means for limiting longitudinal sliding and rotationalmovements of said mandrel relative to said barrel, the end portion ofsaid' mandrel in said barrel being diametrically reduced and providingan abutment shoulder, and sealing means between the mandrel and thebarrel, said sealing means comprising a iirst radially expansible sealunit positioned on said reduced mandrel portion in abutment with saidshoulder, a second radially expansible seal unit positioned on saidreduced mandrel portion in spaced relation from said first seal unit, acompression spring surrounding said reduced mandrel portion and havingits ends in abutment with the respective seal units for spacing the sameapart, the extremity of said reduced mandrel portion beingscrew-threaded, and a nut provided on said screw-threaded extremity inabutment with said second seal unit, said nut being accessible throughthe adjacent end of said barrel and tightening of the nut causing saidseal units to be radially expanded into engagement with the insidesurface of the barrel, and coacting means provided in said barrel and onsaid reduced mandrel portion in engagement with said second seal unitfor moving the second seal unit toward the first seal unit against theaction of said spring and independently of the tightening of said nutwhen the mandrel is slid fully into said barrel.

5. In a suspension drilling device and jar, the combination of a tubularbarrel adapted at one end thereof for connection to a drill stringsection, a tubular mandrel slidable in said barrel and projectingthrough the other end thereof for connection to another drill stringsection, means for limiting longitudinal sliding and rotationalmovements of said mandrel relative to said barrel, the end portion ofsaid mandrel in said barrel being diametrically reduced and providing anabutment shoulder, and sealing means between the mandrel and the barrel,said sealing means comprising a irst radially expansible seal unitpositioned on said reduced mandrel portion in abutment with saidshoulder, a second radially expansible seal unit positioned on saidreduced mandrel portion in spaced relation from said first seal unit, acompression spring surrounding said reduced mandrel portion and havingits ends in abutment with the respective seal units for spacing the sameapart, the extremity of said reduced mandrel portion beingscrew-threaded, and a nut provided on said screw-threaded extremity inabutment with said second seal unit, said nut being accessible throughthe adjacent end of said barrel and tightening of the nut causing saidseal units to be radially expanded into engagement with the insidesurface of the barrel, and a sleeve slidably positioned on said reducedmandrel portion between said nut and said second seal unit, and abutmentmeans provided in said barreland engageable by said sleeve when saidmandrel is slid fully into the barrel, whereby to move the second sealunit toward the irst seal unit against the action of said spring andindependently of the tightening of said nut.

6. In a suspension drilling device and jar, the combination of a tubularbarrel adapted at one end thereof for connection to a drill stringsection, a tubular mandrel slidable in said barrel and projectingthrough the other end thereof for connection to another drill stringsection, means for limiting longitudinal sliding and rotationalmovements of said mandrel relative to said barrel, the end portion ofsaid mandrel in said barrel being diametrically reduced and providing anabutment shoulder, and sealing means between the mandrel and the barrel,said sealing means comprising a iirst radially expansible seal unitpositioned on said reduced mandrel portion in abutment with saidshoulder, a second radially expansible seal unit positioned on saidreduced mandrel portion in spaced relation from said first seal unit, acompression spring surrounding said reduced mandrel portion and havingits ends in abutment with the respective seal units for spacing the sameapart, the extremity of said reduced mandrel portion beingscrew-threaded, and a nut provided on said screw-threaded extremity inabutment with said second seal unit, said nut being accessible throughthe adjacent end of said barrel and tightening of the nut causing saidseal units to be radially expanded into engagement with the insidesurface of the barrel, each of said seal units comprising a pair ofbevelled rings slidable on said reduced mandrel portion, and anintermediate ring of resiliently compressible material interposedbetween said pair of rings, said intermediate ring having bevelledsurfaces complemental to and in engagement with the bevelled rings,whereby the bevelled rings may radially expand the intermediate ringunder pressure imparted axially to the seal unit.

7. In a drilling device, the combination of a tubular barrel, a tubularmandrel slidable in said barrel, said mandrel having a diametricallyreduced end portion terminating in a screw-threaded extremity andproviding an abutment shoulder in spaced relation from said extremity,and sealing means between said mandrel and said barrel, said sealingmeans comprising a first radially expansible seal unit positioned onsaid reduced mandrel portion in abutment with said shoulder, a secondradially expansible seal unit positioned on the reduced mandrel portionadjacent said screw-threaded extremity, a resiliently compressiblespacer interposed between and abutting said seal units, a nut providedon said screwsthreaded extremity in abutment with said second sealI unitwhereby upon tightening of said nut said seal units may be radiallyexpanded into engagement with the inside surface of said barrel, theinterior of said barrel between said seal units constituting a pressurecompensating chamber, a valve provided in said barrel in communicationwith said chamber, and means disposed exteriorly of said barrel andseparably connected to said valve for introducing uid under pressureinto said chamber.

8. The device as defined in claim 7 together with co- 7 acting meansprovided in said barrel and on said reduced mandrel portion inengagement with said second seal unit for moving the second seal unittoward the rst seal unit against the action of said resilientlycompressible spacer and independently of the tightening of said nut whensaid mandrel is slid in one direction in said barrel.

9. The device as dened in claim 7 together with a sleeve slidablypositioned on said reduced mandrel portion between said nut and saidsecond seal unit, and abutment means provided in said barrel andengageable by said sleeve when said mandrel is slid in one direction inthe barrel, whereby to move the second seal unit toward the rst sealunit against the action of said resil-iently compressible spacer andindependently of the tightening of said nut.

10. The device as deined in claim 9 wherein said abutment means comprisean internal shoulder formed in said barrel and engageable by saidsleeve, said sleeve being hollow and accommodating said screw-threadedextremity of the mandrel and said nut therein.

References Cited in the file of this patent UNITED STATES PATENTSRe.20,312 Gates Mar. 30, 1937 1,566,462 Bashline Dec. 22, 1925 1,977,110Burn et al Oct. 16, 1934 2,819,879 Beck Ian. 14, 1958

1. IN COMBINATION WITH A DRILL STRING, A TUBULAR BODY CONNECTED AT ONEEND THEREOF TO A SECTION OF SAID DRILL STRING, A TUBULAR MANDRELSLIDABLY MOUNTED IN SAID BODY AND EXTENSIBLE THEREFROM, THE EXTENDINGEND OF SAID MANDREL BEING CONNECTED TO ANOTHER SECTION OF THE DRILLSTRING, MEANS LIMITING LONGITUDINAL SLIDING MOVEMENT OF SAID MANDREL ANDMEANS LIMITING ROTATIONAL MOVEMENT OF THE MANDREL IN SAID BODY, THE ENDPORTION OF SAID MANDREL IN SAID BODY BEING DIAMETRICALLY REDUCED ANDPROVIDING AN ABUTMENT SHOULDER, A FIRST RADIALLY EXPANSIBLE SEAL UNITPOSITIONED ON SAID REDUCED PORTION OF THE MANDREL IN ABUTMENT WITH SAIDSHOULDER, A SECOND RADIALLY EXPANSIBLE SEAL UNIT POSITIONED ON SAIDREDUCED MANDREL PORTION IN SPACED RELATION FROM SAID FIRST SEAL UNIT,RESILIENTLY COMPRESSIBLE MEANS INTERPOSED BETWEEN THE FIRST AND SECONDSEAL UNITS FOR SPACING THE SAME APART, AND A SCREWTHREADED ELEMENTPOSITIONED ON SAID REDUCED MANDREL PORTION IN ABUTMENT WITH SAID SECONDSEAL UNIT, WHEREBY UPON TIGHTENING OF SAID SCREW-THREADED ELEMENT SAIDSEAL UNITS MAY BE RADIALLY EXPANDED INTO ENGAGEMENT WITH THE INSIDESURFACE OF SAID TUBULAR BODY.